Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon. Dozens or hundreds of integrated circuits are typically manufactured on a single semiconductor wafer. The individual dies are singulated by sawing the integrated circuits along a scribe line.
The semiconductor industry continues to improve the integration density of various electronic components, e.g., transistors, diodes, resistors, capacitors, conductive lines, vias, etc. of integrated circuits by continual reductions in minimum feature size, which allow more components to be integrated into a given area. Some recent reduced feature size conductive line and via designs utilize low dielectric constant (k) insulating materials having a dielectric constant less than a dielectric constant of silicon dioxide for insulating materials, and copper or copper alloys for conductive material. These material systems can present manufacturing challenges in some applications. As an example, copper tends to diffuse into some low k insulating materials, so that the use of barrier layers in the conductive line and via structures is required.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.